Dear All,
I have an ultralight air plane with 912UL mounted. Bought as used at ~400h. Now ~950h. Situation faced after replacement old used up VDO sensor with a new, also VDO type. Now with the latest version sensor version fitted. (thread reshaped from 1/8 NPT to M10x1 with very good thread cleaning)
There is a high oil pressure confirmed with different new sensors and gauges including a mechanical one.
After initial engine start with cold engine it is initially ~6 bar then goes slightly below 5 bar, lets say 4.9 bar during warm up.
During take off (WOT) (oil temp ~70 C) sometimes goes above 5 bar for short period (~5.5 - ~6 bar). Then after up to 10s stabilises very slightly below 5 bar.
Low RPMs - ~4.9 bar. middle RPMs - fluctuating, but within reasonable range (~3 - ~4 bar). Cruise power - ~4.9 bar.
Few 100h/200h maintenances done (oil with filter exchanges). 5y rubber parts exchange done twice, already. Oil always used: Aeroshell Sport +4. Fuel: Mogas.
Oil pump internal blockage checked - none. Still original ball instead of mushroom....
Crankcase pressure checked - 0.1 bar - OK. Engine is burping quite promptly.
Output power OK - performance like other same type aircrafts with such an engine (I have few colleagues with same aircraft type :) ).
Partially blocked oil lines? Shifted crankshaft bearings (not documented overheat by previous user)? Any ideas or solutions? Maybe exchange of ball into a mushroom (and new spring) would help?
I was even thinking about how to back flush oil lines: fill up crankcase with oil, seal crankcase bottom oil output, remove oil temp sensor or a whole pump and put some pressure via opening used for crankshaft blocking and watching what flows out....
ps. I have iRMT Line training.
Szczypas.
